Pour the cereals that you want to use in a large mixing bowl. Then set it aside.

On low heat, melt the butter and marshmallows in a saucepan.

Stir constantly and make sure to melt the mixture completely.

Pour the melted mixture on to the mixing bowl with cereals and mix it well. The marshmallows will get sticky as it cools down so you have to mix it with the cereals quickly.

Then pour the combined cereal mixture to a greased baking pan, spreading it evenly.

Set it aside for about one hour. This will allow the mixture to harden.

Once it cools down, cut it and serve.